DAVAO CITY, Philippines, May 27 (Xinhua) -- Suspected leftist rebels have kidnapped a local couple and four other civilians in southern Philippines, police on Monday said.

Two of the victims were released hours after Friday's abduction in Naboc village, Monkayo town, in Compostela Valley province but the rest are still at the hands of their New People' s Army captors, according to Senior Superintendent Camilo Cascolan, Compostela Valley police chief.

Cascolan identified the victims as lumber trader Lito Armada, 62; his wife Frescielita, and their four employees and local guides.

The police official said the victims were riding a Delica vehicle on their way to scout for lumber products when about ten armed men stopped their vehicle at Community 8, Naboc village, 1 p. m. local time.

The victims were brought to a mountainous part of the village, and the trader's wife and another companion were released some two hours later.

"The suspects were demanding they (couple) pay up revolutionary tax," town police chief Cydric Earl Tamayo said, referring to the so-called taxation by the NPA.

"Four victims are still at the hands of the kidnappers," he said.

Police said families of the victims were allegedly negotiating with the kidnappers for the former's safe release.

"We are investigating the incident," he said.

Friday's kidnapping by alleged NPA rebels came just days after guerrillas also snatched a dozen people in two separate attacks in Mindanao within a 24-hour span. The victims were freed unharmed just over a day after.

The 4,000-strong NPA, armed wing of the Communist Party of the Philippines, is fighting a leftist insurgency in 60 Philippine provinces since 1969.